1. Field
The present invention relates generally to the field of wireless telecommunications, and more specifically relates to establishing priority for a wireless data communication.
2. Background
The demand continues to increase for wireless services including wireless telephony, the wireless transmission of multimedia, wireless e-mailing, Internet access, video streaming, image transmission, and interactive gaming. While a number of systems are in place already, new wireless technologies are being developed to satisfy the growing demand for high speed wireless Internet services. These wireless technologies include, for example, CDMA2000 1xEV-DV, 1xEV-DO, and WCDMA (wide-band Code-Division Multiple Access) which may be used in various forms of voice and data communications. These and other wireless technologies may be used to implement Push-to-Talk (PTT) direct radio voice communication services using various known protocols and specifications.
PTT communications are sometimes known as dispatch communications or “walkie talkie” mode. One advantageous feature of PTT is that a user can communicate with others without dialing an outgoing telephone number. A mobile PTT user may speak with another PTT user, or with a predefined group of other PTT users, by simply pushing a talk button. In current PTT implementations the predefined group of PTT users may include up to one hundred people participating in the same conversation, and possibly more in the future. When making a PTT call a user depresses a button to speak, and all members of the group receive the message. If one of the members of the group responds, all members of the group hear the response. In this way a group of people—say, constructions workers or taxi cab drivers—may carry on a conversation in which all members of the group hear all parts of the conversation. PTT services operate using half-duplex communications, with one channel being used for both in-bound and out-bound communication. Unlike ordinary telephone conversations in which a user may receive and transmit simultaneously, a PTT caller can only transmit or else receive at one given time, but not both at the same time.
A drawback of these and other wireless systems is that they occasionally drop calls or fail to complete new calls, especially during peak usage times or in highly congested areas. This can be a severe disadvantage if the call that is dropped or fails to complete is an emergency communication.